问题 单项选择题 共用题干题

患者男,40岁,右上2缺失,余留牙无异常,咬合关系良好,要求做右上123非贵金属烤瓷桥修复,比色A3 。

烤瓷冠的冠边缘要求中,下列哪项是错误的 ()

A.冠边缘整齐

B.与基牙(或患牙)密合

C.无悬突

D.颈缘与基牙(或患牙)要留有粘固料所需的空隙

E.长短合适

答案

参考答案:D

阅读理解

   LONDON ( Reuters)-- Ecotourism ( 生态旅游) is causing a lot of damage to wildlife and may be endangering the survival(生存) of the very animals people are flocking to see, according to researchers.

Biologists and conservationists ( 自然环境保护论者) are worried because polar bears, dolphins, penguins and other creatures are getting stressed and losing weight and some are dying.

"Evidence is growing that many animals do not react well to tourists in their backyard,” New Scientist magazine said.

The immediate effects researchers have noticed are changes in behavior, heart rates, or stress hormone levels but they fear it could get much worse and over the long term "could endanger the survival of the very wildlife they want to see".

Although money produced through ecotourism, which has been growing at about 10--30 percent a year, has major benefits for poor countries and people living in rural areas, the Swiss-based World Conservation Union and some governments fear not all projects are audited (审计) and based on environmentally friendly policies, according to the magazine,

"The transmission(传播) of disease to wildlife, or small changes to wildlife health through disturbance of daily life or increased stress levels, while not obvious to the casual observer, may translate to lower survival and breeding ,"said Philip Seddon, of the University of Otago in Dunedin, New Zealand.

Scientists have noticed that bottleneck dolphins along the northeastern coast of New Zealand become nervously excited when tourist boats arrive. Similar changes in behavior have been observed in polar bears and yellow-eyed penguins in areas visited by ecotourists are producing smaller babies.

Conservationists are now calling for more research into the effect of ecotourism on animals and say the industry must be developed carefully. They also want studies done before new ecotourism projects are started.

“The animals’ welfare should be very important because without them there will be no ecotourism,”said Rochelle Constantine of the University of Auckland in New Zealand.

72. What's the text mainly about?

A. Many animals are dying because of lack of money.

B. There will be no ecotourism without animals.

C. Ecotourism could endanger the survival of the wildlife people want to see.

D. More research should be done on ecotourism.

73. We may learn from the text that __

A. ecotourism must be developed properly

B. polar bears are losing weight without enough food

C. all the poor countries have stopped ecotourism

D. money produced through ecotourism should be spent on wildlife

74. Which of the following is NOT mentioned in the text?

A. Many animals do not react well in their backyard..

B. Polar bears in areas visited by ecotourists are producing smaller babies.

C. Ecotourism has been growing at about 10--30 percent a year.

D. Studies should be done before new  ecotourism projects are started.

75. What Rochelle Constantine said in the last paragraph implies that __

A. if people want to get high income, they must develop ecotourism

B. animals have rights to live their own life

C. animals are people’s good friends

D. people should take good care of wildlife

单项选择题